Electric valve-grinder.



B. F; STENMAN.

ELECTRIC VALVE '(HINDER. APPLlIcATIoN FILED Mln/24,1913'.

. 1,294,318. Patented Feb. 11, 1919.

2 SHEETS-SHEET l.

gnam/Lto@ I l ezz maz ELECTRIC VALVE GRINDER. APPLICATION FILED 11m24.191s.

1,294,318. u Patented Feb. 11, 1919.

2 SHEETS-SHEET 2.

" UNITED STATES PATENT oEEiCE.

isRoR E. STENEIAN, E WORCESTER, MASSACHUSETTS, AssiGNoR To J. HENRY 'LINDBERQ oF WORCESTER, MASSACHUSETTS.

ELECTRIC VALVEfGRINDER.

Specification of Letters Patent.

Patented Feb. 11, 1919.

' Application filed May 24, 19181. Serial No. 236,402.

and useful Improvements in Electric Valve- Grinders, of whichthe following is a specification.

This invention relates to an electric'valve grinder, and the object is to provide certain novel means for imparting an oscillating movement to the Shaft carrying the bit` whereby an additional movement is secured during the travel, through a givenangle, of the crank arm actuating the shaft.

A further object is to provide for imparting to the crank arm an additional or supplementall movement just before thel arm reaches the limitof its travel in a given direction, thereby increasing the period of frictional contact durinor the travel ofthe arm through a given ang e.

A still further Objectis to provide certain novel means. for connecting the lead wires` with the 'motor actuatin rthe main shaft,

and certain novel vmeans or controlling the switch. y y

A still lfurther object is to provide for vthe employment ofv diiferentforms of Ybits for engaging the valvez certain of the bits including a universal Joint.

With the foregoing and other objects in view, the. invention consists in the novelcolistruction,l combination, and .arrangement of elements hereinafter described and claimed;

In the accompanying drawings: Figure 1 is a view in vertical section,

parts being shown in elevation.

Fig.. 2 is a top plan view.

Fig. 3 isa section on the line 3f-3 of Fig. l. Figs. 4 and 5 are details""showing different positions of the crank arm and pin coperatin therewith.

Figs. 6 to 9 are' details showing different forms of bits. v v

Fig. 10 is a bottom plan view of Fig. 9.

Fig. 11 is asectio'n .through the handle, showing certain elements of the'switch.

Fig. 12 shows one of the operating pins 'detached from the slidable member'of the swi-tdi.A l

Acasin includes an upper casing member 10 i'i 'a lower, casing member 12 carry'- ingfa tubular extension 14,-' 'Said member 12 being secured inposition by means of screws such as 15- entering the plate member 16 located between the two casing members. Plate member 16 is retained in posit-ion by means of rods 1T threaded at their ends and engaged by nuts at-the opposite ends thereof.

The motor 20 is shown more or less conventionally and the armature shaft 21 cai'- iies a pinion 22 meshing with`a gear wheel' 23 having a pinion 2l rigid therewith.

This pinion 24 meshes with the gear wheel 25 mounted on a short shaft 26. Gear wheel 25 carries apin 2T engaging and operating l a .slotted aim 30. The slot 31 of the arm is of the form Shown and serves a particular Vpurpose as specified below. Arm 30 is rigid with reference to shaft 32 passing through the tubular member 1l, and imparts to the Shaft an oscillating movement.

A sleeve 33'is keyed to Shaft 32 in any Suit-able mannersuch as b v passing the pin 34: through the' sleeve and shaft.

the end of member 14.

,Sleeve 33 is slotted transversely as Shown at`38, and withinthis slot isl mounted a bit, the latter being secured by means of a pin 39. The bit showninFig. 1 is designated 40 and is designed to engage an engine valve of the type having two spaced aper- A loose washer 35 is located between tlie'sleeve andtures formed therein. This bit is also shown in Fig. 7, and in Fig. v8 I have Shown a bit vconnected .at -16l with an element 47 which in turn is connected by pivot 18, extending at another angle, witli eais 19 carried by disk 43. This construction provides a Substantially universal movement between the shaft' 32 andthe valve engaged b v disk 43 and the pins' thereon.

Referring to -Figsl and 5, Special attention is directed to the formation of the Slot 31, the purpose being to provide for an ad' ditional or supplemental movement of the valve within the extreme limit of movement thereof, thus increasing the eifective frictional Contact during each complete ioo movement of the arm 30. Jut before arm reaches the limit of vement in either direction, it is mo twardly to a slight extentwith ref 'i theA main 1movement of the arm atfthis particular instant, the arm then again moving forwardly to. thellimit of its travel in that direction, at' whlch time r'the'. direction of the movement is Y and the terminals, the latter not being shown.

In Figs. 1I and 12 I have shown certain details of the switch which may be employed. This switch is mounted 1n the delected tubular portion 55 of the handle and Amember has pivotally connected therewith springs 58 engaging a cutfaway is under the control of .detachable pins 56 and 57, the pins being removable 1n order to revent the manipulation of the switch by vindiyidual's not authorized touse the im.

plenient. ,Each pinA carries `a plurality of l portion 59 of the slidable member 60. This slidable -a'pin 61 passing loosely through the central portion vof a yoke 63, a spring 6l being interposed as shown for a purpose readily ap- Lea/.16,318

parent. Yoke G3 is pivotally mounted in ears 6l, and the slide\60 is movable transversely of the yoke by the operation of either pin 56er 57. This movement of the slide 60 throws the yoke into engagement with upwardly extending Spring elements G6 so located as to be engaged by the cent-ral portion of the yoke, for the purpose of completing an electric circuit including the motor 20.

That is claimed is:

1; In a device of the class described, a casing, a motor mounted therein, a shaft to be driven by the motor, a bit carried by the shaft, an arm mounted on the shaft for imparting an oscillating movement thereto, a gear wheel, means for driving the latter from` the4 motor, and a pin carried lby the v gear wheel, said arm being slotted, andthe slot thereof being of luniform. width and ex tending in two directions with reference to the main axis of the arm.

2. In a device of the class described, a casing, aj motor mounted therein, a shaft, a bit carried by the shaft, an arm for imparting an oscillating movement to the shaft and the bit, said' arm being slotted lengthwise and including an angular portion, a wheel drlven from the motor, a pm carried by the wheel and extendingl into the slot, said slot being proportionec' to impart an additional oscillating movement to the arm, within the limits of the principal movement thereof.

In testimony whereof I aiix my signature.

BROR F. STENMAN. 

